Question

a number of 2digits whose sum is 7.if 9 is added to the number,the number,the digits change their places. then the number is​

Answer 1

Step-by-step explanation:

let the of 2 digit be x

hence,10x

10x + 9 = 7

10x=7-9

10x= -2

x=-2/10

x=-1/5